U.S. regulators are moving to get rid of unhealthy trans fat from Americans' diets, but critics are warning that a common replacement, palm oil, is not that much healthier and also bad for the environment.
The push to eliminate added trans fats from the American diet has prompted an increase in the use of palm oil, which is harvested from the fruit of palm oil trees growing in the rainforests of Malaysia and Indonesia. The destruction of the forests threatens endangered species like orangutans, Sumatran tigers, and elephants, environmentalists say.
"The concern is that a lot of companies will switch to palm oil in order to reduce trans fats without thinking more broadly about the health and environmental implications of that," said Bill Barclay, Policy and Research Director for the Rainforest Action Network. "They're losing critical habitat that threatens their survival and that's largely driven by palm oil expansion."
Palm oil production has exploded over the past few decades to keep up with commercial demand. Palm oil is solid at room temperature which makes it a good substitute for trans fat. The drive to get Americans to eat less trans fat and the low price of palm oil have led to an expansion of the palm oil industry.
Trans fat was a common additive to snack foods, until it started coming under fire as an artery-clogger that increases risks of heart disease. Partially hydrogenated oils -- vegetable oils treated with hydrogen to make them solid at room temperature -- contain trans fat and are added to foods to improve the texture and increase the shelf life. Earlier this month, the Food and Drug Administration proposed eliminating trans fat altogether because it's no longer considered a safe food additive. The FDA hasn't yet said how long companies would have to make the change, but a timeline could be decided as early as January.
Though scientists agree trans fat is unhealthy, the effort to get rid of it has raised questions about what should replace it.
"The problem is that there are certain foods that could not be made without a solid fat," said Prof. Eric Decker, who studies food science at the University of Massachusetts Amherst. Decker said that the trans fat ban will likely increase the use of palm oil.
"Cookies and crackers and pastry doughs aren't going to go away," Decker said. But he's concerned about the unintended health consequences of the trans fat ban. Palm oil has 50 percent saturated fat and Americans already eat too much saturated fat, he said.
"Whenever you talk about taking fat out of the diet you have to talk about what's going to be the substitute," said Prof. Alice Lichtenstein, who studies nutrition at Tufts University. Lichtenstein studied what would happen if trans fats were replaced with palm oil and found that there was no health benefit. But she points out that companies don't have to use palm oil -- they could use other types of oil that aren't as high in saturated fat. Lichtenstein said that the overall effect of eliminating trans fat would likely have a public health benefit.
Though the ban could increase U.S. consumption of palm oil, the biggest increase may already have occurred because many companies have already made the switch.
"Since companies have been required to label trans fat, many of them have voluntarily moved away from it," said Doug Boucher, Director of Climate Research and Analysis at the Union of Concerned Scientists, which produced a report last year criticizing the palm oil industry for destroying the rainforest.
Boucher said palm oil cultivation could be changed, so that it has less of an impact on the environment. "It has the potential to have some positive climate impacts if it's grown on the right time of soils," Boucher said.
Despite problems with palm oil, Boucher said the health effects of trans fat are clear. He said the FDA's decision is justified, "even though it has some boomerang effects on the palm oil industry."